The present invention relates to an electrically-operated steering lock device which is prevented from locking the steering shaft even if an electrically-operated member has malfunctioned due to noise or the like.
A conventional electrically-operated steering lock device, as disclosed in, for example, Japanese Patent Laid-Open Publication No. 2002-234419, is so designed that a lock shaft is driven by a plate cam coupled to an electric motor so that the lock shaft is protruded toward a steering shaft so as to be engaged with the steering shaft, and thus locked. Further, with an engagement recessed portion formed in the plate cam, a plunger of a solenoid is engaged with the engagement recessed portion so that even if the electric motor malfunctions, the lock shaft is prevented from popping out by keeping the plate cam from rotating with a hold by the plunger.
However, in such electrically-operated steering lock device, there has been a problem that when the solenoid and the electric motor are simultaneously driven due to noise or the like during running of a vehicle, the solenoid may pull in the plunger so that its engagement with the plate cam is released, where at this timing of releasing, the electric motor rotates to make the lock shaft protrude toward the steering shaft, thus locking the steering shaft.